Which testing method allows researchers to determine if there are statistical differences between group means?

The correct answer is ANOVA, which stands for Analysis of Variance. This statistical method is specifically designed to compare the means of three or more groups to determine if at least one group mean is statistically different from the others. ANOVA assesses overall variability among group means and the variability within groups, effectively partitioning the total variance in the data.

By calculating the F-statistic, ANOVA helps researchers decide whether any observed differences are significant or could have occurred due to random chance. This makes it particularly useful for experiments or studies that involve multiple groups.

For comparing only two groups, other tests like the paired t-test or the Mann-Whitney U Test are applicable; however, they are not designed for evaluating differences among three or more groups, which is where ANOVA shines. Thus, when researchers want to assess whether there are any statistical differences among multiple group means, ANOVA is the appropriate method to use.